This invention relates to a method and apparatus for connecting a trailer in a tractor-trailer assembly, and more particularly to a method and apparatus for positioning a rear trailer behind a front trailer in a tractor-trailer combination for connection therewith.
In the trucking industry, more and more states are permitting the hauling of freight over the road in more than one trailer, connected in tandem with a tractor. The connection of a single trailer to a tractor is relatively simple since the tractor carrying a sloping fifth wheel connector on the rear of its chassis is backed up beneath the front end of the stationary trailer until the connector pin or ball at the front end of the trailer is properly seated within the socket of the fifth wheel connector. However, the connection of a second trailer to the rear of the first trailer is more involved and takes substantially more time than the connection of one trailer to a tractor, in the order of 45-50 minutes.
In order to assemble two trailers in tandem to a tractor, the tractor is first connected to the front end of a front trailer in a conventional manner, that is by backing the tractor beneath the front end of the trailer. However, since conventional trailers are not equipped with fifth wheel connectors, a separate mobile carrier supporting a connector member, and specifically a fifth wheel connector, must be located and connected by its tongue to the cooperating connector on the rear end of the front trailer. This tandem assembly, including the tractor, the trailer and the mobile connector carrier, known in the trade as a "JIFFLOX", is driven to a position as close as possible to the front end of a second or rear trailer. Since the assembly cannot be backed up or moved rearwardly more than approximately twelve feet without the connector carrier jack-knifing, the operator of the tractor must first manually unhook the carrier from the rear end of the front trailer and push it by hand to a position as close as possible to the front end of the rear trailer. Then the operator returns to his tractor and backs the front trailer slowly and carefully toward the carrier, attempting to stop approximately one foot before the rear end of the front trailer engages the tongue of the carrier. This part of the operation is extremely tedious since the driver or operator must use extreme caution in lining up the front trailer and the carrier with the rear trailer so that after the carrier is re-connected to the front trailer, the carrier does not jack-knife as the front trailer is moved rearwardly toward the front end of the rear trailer. Moreover, care must be taken not to strike the tongue of the carrier with the rear end of the front trailer, which is invisible to the operator as the tractor and front trailer move rearwardly.
After the front trailer is moved as close as possible to the carrier, the operator again gets out of the tractor, goes to the rear of the front trailer and manually re-connects the carrier to the rear of the front trailer. The operator again returns to the tractor and backs up the front trailer and mobile connector carrier until the connector pin on the front end of the rear trailer seats in the fifth wheel socket of the carrier. All of the vehicles which are elements of the tandem assembly are now connected. The dollies on the rear trailer are elevated and the air and electric lines are connected to render the entire tandem assembly road-ready.
Certain types of laterally shiftable platforms for supporting the wheels of motor vehicles are known, as shown by the following U.S. patents:
______________________________________ 2,924,389 Anderson Feb. 9, 1960 3,199,783 Hurst Aug. 10, 1965 3,746,251 Bernardi, et al Jul. 17, 1973 3,786,988 Thompson Jan. 22, 1974 ______________________________________
All of the above patents disclose various types of transversely moveable plates, located beneath a wheel guide, such as a wheel guide used in a car wash apparatus. The purpose of the plates is to move transversely with the front or rear wheels of the moving vehicle, supported on the plate, when the wheels engage the wheel guide off-center. Forward movement of the vehicle causes the wheels and the transverse plate to move to position the wheels in alignment with the wheel guides.